The present invention relates to an image reading device capable of image reading from a stationary original and image reading from a moving original.
Conventionally, image reading devices have been known that are capable of image reading from a stationary original and image reading from a moving original. Image reading from a stationary original is performed by reciprocating an image sensor with respect to a platen glass where the original is placed. Such image reading is known, for example, as an image reading device called a flatbed type. On the other hand, to perform image reading from a moving original, the original is conveyed to the reading position of the image sensor by an original conveying mechanism that conveys the original along a predetermined conveyance path, and image reading is performed when the original passes through the reading position. As such an original conveying mechanism, for example, one called an auto document feeder (hereinafter, referred to as “ADF”) is known.
FIGS. 1 and 2 are perspective views showing a conventional image reading device capable of image reading from a stationary original and image reading from a moving original. A multi function device (MFD) 90 integrally comprises a printer unit 91 below and a scanner unit 92 above, and has a printer function, a scanner function, and a copier function. The scanner unit 92 of the multi function device 90 is an image reading device that performs image reading from a stationary original and image reading from a moving original.
In the scanner unit 92, an original cover 94 is openably and closably provided on an original table 93. A platen glass 95 is disposed on the top surface of the original table 93. When a stationary original is read, the original is placed on the platen glass 95. An image reading unit having an image sensor is provided inside the original table 93. As the image sensor, for example, a contact image sensor (hereinafter, referred to as “CIS”) is used. By this image sensor being moved parallel to the platen glass 95, image reading from the original placed on the platen glass 95 is performed.
As shown in FIG. 1, the original cover 94 has an ADF 96. The ADF 96 conveys the original along a predetermined conveyance path from an original tray 97 to an output tray 98. These two trays are disposed one on the other on the top surface of the original cover 94. As shown in FIG. 2, an opening 99 for reading a moving original is formed on the lower surface of the original cover 94. The original conveyed along the conveyance path of the ADF 96 is exposed to the platen glass 95 when passing through the opening 99. A partial area of the platen glass 95 opposed to the opening 99 when the original cover 94 is closed is a reading surface for reading a moving original. When a moving original is read, the image sensor is stopped below the reading surface. Then, the image of the original passing through the opening 99 while being conveyed by the ADF 96 is read by the image sensor.
The CIS used as the image sensor is moved in a direction orthogonal to a reading line with one direction of the platen glass 95, that is, the direction of the width or the depth of the platen glass 95 as the reading line. In the scanner unit 92, to read the original passing through the opening 99 by the ADF 96, the image sensor is disposed so that the same direction as the direction of the length of the opening 99, that is, the direction of the depth of the platen glass 95 is the reading line. On the other hand, in image reading devices of the flatbed type not having the ADF, the image sensor is sometimes disposed so that the direction of the length of the platen glass is the reading line (see, for example, Japanese Patent Application Laid-Open No. 2002-290680).